You can make a small fire and not leave any more trace than a hobo stove if you do it right. Takes a little longer. Colder weather always requires a little more fuel. When its really cold, like 10degF, its hard to tell good dry wood from wood that is wet but frozen. It's worth bringing a strong knife or small hatchet or folding saw so you can get into some dry wood from larger deadfall and make it into smaller pieces for a smaller fire. Fun stuff, and sustainable, and reasonably LNT depending on the habitat and traffic. Not sure how well it would work on the AT, but I would imagine its do-able especially more off season. Worth carrying some fuel and coals and tinder for the next fire, and if you do that you may as well bring a hobo stove or kelly kettle to carry it in.